Is it okay to idle the car overnight with the air conditioning on?
2 Answers
Yes, but prolonged idling can cause significant harm to the car. Here are the specific details: Idling can easily lead to oil burning: During idling, the throttle opening is small, and the vacuum level inside the intake manifold is high, making it easy for oil vapor to be drawn into the intake manifold. Some of it deposits inside the intake manifold, forming carbon-like substances, or what is known as coking. Prolonged low-speed operation or idling, especially in turbocharged models, can result in a pool of oil behind the throttle in the intake manifold. However, this oil usually disappears after driving at high speeds. Idling can easily cause carbon buildup: During idling, the air-fuel mixture tends to be richer, so prolonged idling with a richer mixture can easily lead to engine carbon buildup.
As a veteran driver with over 20 years of experience, I must warn you not to do this - leaving your car idling overnight with the AC on is extremely dangerous. One winter I slept in my car with the AC running and soon felt dizzy and nauseous - turns out it was carbon monoxide poisoning. That invisible, odorless gas can accumulate in the cabin when parked in garages or unventilated areas, causing anything from fainting to death. Since the AC relies on the engine, the emission system can't handle the toxic gases properly at idle speed, especially in older models that may have leaks. Safety first - only use AC briefly when parked with windows slightly open, but never overnight. For cooling needs, try using a car fan or precooling before parking. Don't gamble with your life. Remember, accidents often stem from carelessness - learning preventive measures can save lives.
